Quoit



Jan. 8, 1935. J, MacGREGOR 1,986,937

QUOIT Filed Sept. 10, 1932 10001! fl/dCPZU? IN V EN TOR.

' SW 7i fin ATTORNEY animatio remtes t'o the Patented Jan. 8, 1935 V metallic articles, the surface's off wqi-ic signed; to exhibit reas or eon-nastineeegrees of hardness. sf-In "the preferred mode of carrying 'hardening f, the metallic article' during its manufactureispreliminarily-formed with rais'ed or protuberant portions offexcess' were; it coinciding g 'here hard gappearuponahemusk; the article, which will usuallybe at tho'se*pl-'aces where the article in use is most subject to wear or shock. After the article has been decarbu-rized its surface r Tease-softened; to ptovide it with'a thin crus assert metal; the pi'otuberant are "out -away llush with the stu' face to expose the unaltered metal beneathdhis crust. Finally the'iarticle is fsubjected to" uita-hle heat treatment to harden and temper throu'ghout at which tirne th'e spots of exposed inner metal will a n a hardness andtem w m core while the "soft surface acrust will "remain relatively unaffected "by this treatmen't: Alter natively; the protuberant portibris may beraliowed to remain upon the mica until afterii-t hast been hardened and tempered,"these portions bing ground offin 'ahfini'shi-ng' opei atiorilto expose sorter-metal? a the hard metal' lbene the .i'surface crust of 1: While the process of the invention in i its broader aspect ismct limited to theimaking of any specific articles, nevertheless Lit Ifinds espe cially useful application theimamrfacmre; of quoits; T used" -.tl.'ie.rg"ame-:"ofv quoits; wand results :in" the; production ofzasquoit :icfga improved construction. According to present practice; quoitsL'cominonIyarLmade by either casting or forging. Quoits made by casting, however, are particularly susceptible to chipping and breakage because of their relatively brittle composition; and, because of the frequent occurrence of latent defects in quoits madeby the ordinary methods of casting, they are liable to fail under shocks caused by the pounding of one quoit upon an other in play. 7

Quoits madeby forging, on the other hand, are according to present practice usually composed of relatively soft metal such as may be flowed between dies during manufacture so that their relatively thin circumferential edges soon Letit a; MacGregorQAllentown, ass gn r d'liu lworksla'corporatiq o their surfaces to -retardi kidding of'son quoit uponanother and, =to' 'a'; ertain extent, to reduoe shoclrrc'aused by-ithe cla of therquoits against eachiother when=in --'use,w A

115B) -my process "a strong'er and more durable i type or kiu'oit can be? cheaply iandexpeditiously produced; and-one which is free of the objections inherent in thosei' nowknown. 1 In applying the process to the manutacturepftquolts, thequ'oit forging mean-3w formed with i an": overlay of excess:metal?"upon its 'circumference; 'I'he'n the fcrging designedly is' decarburized 'upcnits surface, the overlay metal ground Taway to reveal the l'inner metal, and the forgingfinally heat treated td h'arden and tempera it; or the forging may be hfardened'and -temperedi'before removal of i the 'excess metalli ms produces- 211 quoit having a circumferential rim of very hardwmetal which will mut -chip nor defbrmzaften prolonged use, while the remainder-cr me qubi't is' covered withla crustpfsoft' matermlihavingthe advan tages before desclsibedz it 'I'hei i z-r vei-ittonwill bei'i hetter lunderstoodi from the following detailed description 4 of tone" preferredmod'eof' practicingrthe? processof" 1 my 'mve thereby, reference "heir! drawing i which-M l Figure i's a planiew of a quoit iforging as it appears at; the stage after decarbur ization had to the annexed n 'Figure I is $18. a cross section =01? the forging :of

Fig. rtakenalong' its di'ameter; i I

- Figure- 3"is a cross-section=of the same forging after removal of '-:the excess t meta-1' upon its circumference and: after hardeni'ngs and tempering;

a ring-like metal disk 1 provided with a sub-' stantially flat but slightly concaved bottom side 2 and a convex top side 3. While this forging cumference there is provided an overlay of excess metal which is designed to be removed in a subsequent stage of manufacture. This excess metal constituting its core or bodyiand-which was a in an oxidizing atmosphe the metal homogeneous throughout, as is W'lli;

known in theart, is heated for a ut'fourh urs perature of about 1450, degi' F. burize the outer surfaceoftheforging and provide it with a skin or crust ofsoft metal; -'Ihis crust need not penetrate beyond 1/ 32nd,,or 1 /1;6th

of an inch and in any event ought not'to exceed the. thickness of therings ,of metal land 5., This decarburization treatment, robsithe surfacevv of the forging of aglargepartiof its carb,on;in the-"case of silico-manganese steelias specified the carbon content is ,reduced :from; approximately 50. per cent to approximately; ;.-20 per .cent-; b1 1;t the; initerior" metal of .the forgingzis substantially. un aifected by! this treatment --and;retains itsorigia nal:relatively.high carboncontents-:3 4 I Following:decarburization, thej forging is placed in alathe and: the protuberant-rings of metal:;4 and 5tare'groundwofflby: an abrasivejwheel or other suitable means to adepthcorrespondingto thev dotted line surface shown in',Fig.;4-.-t0;i expose upon the circumference of the forging-the interior quarters of an: hour; andyithen, quenched in1-oi1;

By this operation the annulus of' core metalwhich :wasb'rought to light-by .theremoval; of therings 4 and; 5 and which containsits.original:high;per+

, centa'gecf carbon wilLtakeaon; an .intense'h'ardness; while the surface of, the-'forgingwhich was softened the: preceding decarburizing treatment andxwhi'ch is ;of relatively slow carbon con.- tent on1yabout :20: per cent, inithe case; of- .the silico-manganese steel mentioned above-willbe impervious :to'v the treatment; Consequently; the surface crust will remain substantially unchanged and will :retain'its former attributes. f;

As the concluding step of this heat treatment, the forging is heated at a temperature of about 700 degrees F. for about two hours to impart to it the proper temper, in a manner which is well understood in the art, resulting in a quoit as illustrated in Fig. 3, constituted of a core and circumferential edge of intense strength and hardness and asuperficial crust of softer metal.

lit not necessary tha'tthe removal ofthe rings of excess metal'precede the' hardening and tem- .-p ering step. For example, the method of the invention may be carried out by initially decarburizfing the surface of theforging to impart to it a rust o ff soft., metal, then hardening and temperng 'thejbodyof 1 theforging as before described.

"The ringsAand '5 w:il l then be removed to develop the circumferential rim of hard metal. In this event 'liowever; the" excess metal will be very resistant because of prior hardening, but'its removal may be accomplished by an abrasive wheel.

Ibimbvious hat rust t-coatin .OfIs metakmaybe-appliedto the forgingin ways other than those iwhich have been described. Foneg: ample-this may be accomp d pp na; by sherardizing or by eleetr -deposition,the circume encethefo in bein ea o tn-$50 mg -material; ina subsequent operation 1 01; a pa a-terimo d-.-m ta ay b hr k 1 9 thecircumference of the forging. SuGh ;a nov;el 0 m=-.- f; qu i r e t veqo h w-:pr0du d,:=is deemed to fall Within the purview. of this 1inven+ Mon wvl claim: I 1;; A-quoit having va core of relatively hard metal and a superficial crust of soft metal-covering sub,- stantially the entire surface-of 1.11118 -.core,,except upon its circumferenceni j g,;..- q -2;. A:quoit having a coreof relatively hard metal and-a superficialscrust of soft metal locatedl a spaced distance inwardly of the circumference of the quoit.- 1 .1 I: 3. 'A-quoit having a core-of relatively hard-metal and' a superficial crust of softmetal-covering the major portion ofits surface, the r said core,- :and crustbeing 0151113116 samekindjof metal but of different. degreesgof hardness. 1 44.:A quoit of; disk formihaving a;core of relatively -hard metal and a thin superficial-crustof soft metal integrally united with the, coreirisaid crust; covering the upper and-.lowerqsurfaces' of the,quoit-anditerminating a-spaceddistance from its 'circumferencei- 11- v511; 1::- w: I '5.".A steel .quoithavinga corelof relatively-high carbon contentand'a crustof relatively low carbonllcontent covering the major.; portion of its 

